That is an interesting play on words. Has anyone adapted a 1938 speedometer to work with a 1994 NV4500 transmission?
Adapting a 1938 Chevrolet truck speedometer to go in a 1994 GMC or Dodge truck. Nah! That would be weird, put hey, anything goes in the world today.
From what little I know about the NV4500:
The transmission has a mechanical driven gear that drives a mechanical-electronic module that generates a 5 volt square wave signal for an electronic speedometer.
So can we modify a cable driven 1938 speedometer that is basically a clock spring, magnets and a movement to operate on a 5 volt square signal? Nope.
What if:
Transmission side. Ditch the electronic module. Use the driven gear and R&D a mating gear (gear ratio TBD) to cable drive connector. The problem is we don't know if the MOPAR driven gear is strong enough to operate a cable that goes all the way to the dash with many bends along the way. That may be too much for a plastic gear. Probably not a good idea.
Dash side: Buy a speedometer that is NV4500 signal compatible, physically alter it to the size of a 1938 speedometer and slap a 1938 speedometer face decal on it. Not a good idea either because that's a lot of work and it may not be compatible if the owner wants to keep a 6 volt battery system.
